Friction damper

ABSTRACT

A friction damper includes: a base body; a support secured to an elongated member of the base body and having a through hole; a rod which extends in such a manner as to pass through the through hole of the support and is movable in an axial direction with respect to the support; a friction member which has a hollow cylindrical portion interposed between the support and a main body portion of the rod in the through hole of the support, and which is fixed immovably with respect to the relative movement of the rod in the axial direction with respect to the base body; and a tightening device provided for the support so as to tighten the hollow cylindrical portion of the friction member onto the main body portion of the rod.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.11/882,980, filed Aug. 8, 2007, now pending, which is a divisional ofU.S. application Ser. No. 10/501,473, filed Jul. 14, 2004, now U.S. Pat.No. 7,322,451, which is a U.S. national phase of InternationalApplication No. PCT/JP/00256, filed Jan. 15, 2003, which designated theU.S. and claims the benefit of Japanese Application No. 2002-007740,filed Jan. 16, 2002 and Japanese Application No. 2002-376892, filed Dec.26, 2002, each incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a friction damper which is installedbetween a pair of members that are displaced relative to each other andwhich dampens displacement as speedily as possible by absorbing thedisplacement energy between the members through friction. Moreparticularly, the present invention concerns a friction damper whichdampens displacement as speedily as possible by absorbing thedisplacement energy occurring in structures such as office buildings,multiple dwelling houses, detached houses, bridges, and the like due toearthquakes or the like.

BACKGROUND ART

As dampers for speedily damping vibrations such as lateral shakingoccurring in a structure due to an earthquake or the like, those usingthe viscous deformation of a viscous material, those using the plasticdeformation of lead, steel rods, or the like, and those using thefriction of a sliding member, among others, are known.

In the damper using a viscous material, much time is required in thecharging operation of the viscous material, and it is necessary toprovide a tight seal for preventing the leakage. In the damper usinglead, a steel rods, or the like, there is a risk of environmentalcontamination due to lead, and it is required to firmly hold both endsof lead, the steel rod, or the like, respectively, to a pair of memberswhich are displaced relative to each other.

Meanwhile, In the damper using a sliding member, there is a possibilityof deterioration in characteristics due to the wear of the slidingmember. Further, a sliding layer of the sliding member can peel off,which can also possibly cause deterioration in characteristics.

The present invention has been devised in view of the above-describedaspects, and its object is to provide a friction damper which has asimple structure, is capable of reducing wear and the exfoliation of thesliding layer as practically as possible, and makes it possible toobtain stable damping characteristics over a long period of time.

DISCLOSURE OF THE INVENTION

The friction damper in accordance with a first aspect of the inventioncomprising: a base body adapted to be capable of being attached to oneof a pair of members which are displaced relative to each other; asupport secured to the base body and having a through hole; a rod whichextends through the through hole of the support, is movable in an axialdirection with respect to the support, and is adapted to be capable ofbeing attached to another one of the pair of members; and a frictionmember which has a hollow cylindrical portion interposed between thesupport and the rod in the through hole of the support, and is fixedimmovably with respect to the relative movement of the rod in the axialdirection with respect to the base body, the hollow cylindrical portionof the friction member having a mesh-like base material disposed on aradially outer peripheral surface side thereof and a syntheticresin-made sliding layer filling meshes of the base material and formedon one surface of the base material, and the sliding layer beingdisposed on radially inner peripheral surface side of the hollowcylindrical portion so as to be brought into contact with the rodslidably in the axial direction.

In accordance with the friction damper according to the first aspect,the base material of the friction member is a mesh-like material, thesliding layer of the friction member is formed on one surface of thebase material in such a manner as to fill the meshes of the basematerial, and such a sliding layer is disposed on the radially innerperipheral surface side of the hollow cylindrical portion so as to bebrought into contact with the rod slidably in its axial direction.Therefore, it is possible to avoid wear with respect to the rod aspractically as possible, and obtain stable friction. Furthermore, it ispossible to avoid the exfoliation of the sliding layer. Hence, it ispossible to obtain stable damping characteristics over a long period oftime.

The friction damper according to a second aspect of the invention, inthe friction damper according to the first aspect, further comprises:tightening means for tightening the hollow cylindrical portion of thefriction member against the rod. Here, the through hole of the supportand the hollow cylindrical portion of the friction member is reduciblein diameter, and the tightening means is adapted to reduce the diameterof the hollow cylindrical portion of the friction member through thereduction in diameter of the through hole of the support to tighten thehollow cylindrical portion against the rod.

In accordance with the friction damper according to the second aspect,the hollow cylindrical portion of the friction member can be tightenedonto the rod by the tightening means by being optimally adjusted.Therefore, by a simple operation, optimal frictional resistance can beobtained for the pair of members which undergo relative displacement.

As in the friction damper according to a third aspect of the invention,the support preferably has a slit communicating with the through holeand is thereby reducible in diameter. In this case, as in the frictiondamper according to a fourth aspect of the invention, the tighteningmeans preferably has a bolt threadedly engaged with the support, so asto be able to reduce the width of the slit.

In addition, as in the friction damper according to a fifth aspect ofthe invention, the support is preferably formed into two-split membersand is thereby reducible in diameter. In this case, as in the frictiondamper according to a sixth aspect of the invention, the tighteningmeans preferably has a bolt threadedly engaged with the support, so asto be able to reduce the width of a gap between the two-split members.

The hollow cylindrical portion of the friction member in a preferredexample has a slit extending from one end face to another end facethereof in the axial direction, and is thereby reducible in diameter asin the friction damper according to a seventh aspect of the invention,or is formed into two-split members and is thereby reducible in diameteras in the friction damper according to an eighth aspect of theinvention.

In the invention, as in the friction damper according to a ninth aspectof the invention, in addition to the hollow cylindrical portion, thefriction member preferably has a collar formed integrally with thehollow cylindrical portion, and is fixed immovably with respect to therelative movement of the rod in the axial direction with respect to thebase body at the collar.

It should be noted that an annular groove may be formed in the innerperipheral surface of the support in the through hole of the supportsecured to the base body, and the friction member may be fitted to thisannular groove, whereby, instead of or in conjunction with theabove-described arrangement, the friction member may be fixed immovablywith respect to the relative movement of the rod in the axial directionwith respect to the base body.

In accordance with the friction damper according to a 10th aspect of theinvention, in the friction damper according to any one of the second toninth aspects, a plurality of supports arranged in the axial directionare provided, and the tightening means and the friction member areprovided for each of the supports.

In accordance with the friction damper according to the 10th aspect,displacement energy is adapted to be absorbed by the plurality offriction members. Therefore, as a result of the fact that the loads ofthe respective friction members can be reduced, it is possible to obtainstable damping characteristics over a long period of time.

The friction damper in accordance with the invention is not limited tothe one having a plurality of such supports and friction members, andthe friction damper may have a single elongated support and a singleelongated friction member. In this case, an arrangement may be providedsuch that the elongated hollow cylindrical portion of the singlefriction member is tightened against the rod by the tightening meansconsisting of a plurality of bolts and the like by means of the singleelongated support.

In accordance with the friction damper according to an 11th aspect ofthe invention, in the friction damper according to any one of the secondto eighth aspects, a plurality of supports arranged in the axialdirection are provided, and the tightening means and the friction memberare provided for each of the supports, and, in addition to the hollowcylindrical portion, each of the friction members has a collar formedintegrally with the hollow cylindrical portion, and is fixed immovablywith respect to the relative movement of the rod in the axial directionwith respect to the base body by being clamped by the supports adjoiningat the collar.

In accordance with the friction damper according to the 11th aspect ofthe invention, in the same way as the friction damper according to the10th aspect, displacement energy is adapted to be absorbed by theplurality of friction members. Therefore, as a result of the fact thatthe loads of the respective friction members can be reduced, it ispossible to obtain stable damping characteristics over a long period oftime. Furthermore, the respective friction members are fixed immovablywith respect to the relative movement of the rod in the axial directionwith respect to the base body by being clamped by the supports adjoiningat the collars. Therefore, the respective friction members can be firmlyfixed, so that it is possible to eliminate the drawback that thefriction members are offset from the supports.

As in the friction damper according to a 12th aspect of the invention,the base material preferably comprises one of an expanded metal and ametal wire net. The expanded metal is formed such that a multiplicity ofslits are cut in a metal sheet, preferably a metal sheet made ofphosphor bronze, and the metal sheet made of phosphor bronze with themultiplicity of slits cut therein is drawn in a direction perpendicularto the slit direction. The metal wire net is formed by weaving orknitting by using one or two or more fine metal wires comprising astainless steel wire, such as austenitic SUS 304 and SUS 316 or ferriticSUS 430, an iron wire (JIS-G-3532), a zinc-plated iron wire(JIS-G-3547), a copper-nickel alloy (cupronickel) wire, acopper-nickel-zinc alloy (nickel silver) wire, a brass wire, aberyllium-copper wire, or the like.

The sliding layer preferably contains polyimide resin as in the frictiondamper according to a 13th aspect of the invention, or containstetrafluoroethylene resin as in the friction damper according to a 14thaspect of the invention.

In accordance with the friction damper according to a 15th aspect of theinvention, in the friction damper according to any one of the first to14th aspects, the base body includes a tubular body; one cover securedto one end portion of the tubular body and having a through hole throughwhich the rod is passed; and another cover secured to another endportion of the tubular body and having a fitting attached thereto forbeing attached to the one member. Here, the support being secured to aninner peripheral surface of the tubular body.

In the invention, as the friction member, the following one is suitable.The sliding layer formed of polyimide resin, tetrafluoroethylene resin,or a mixture thereof is formed on one surface of a metal sheet(mesh-like metal sheet) formed of an expanded metal or metal wire nethaving a multiplicity of meshes, in such a manner as to fill the meshesof the metal sheet, as described above. The metal sheet having such asliding layer formed on one surface thereof is cut into strips. Thismetal sheet in the form of strip is convoluted by one turn such that thesliding layer is set on the inner peripheral surface side, therebyforming a hollow cylinder having a slit formed between mutual abutmentends of the metal sheet and extending from one end face to the other.Subsequently, this hollow cylinder is subjected to press forming,thereby fabricating the friction member which integrally has the hollowcylindrical portion and the collar.

The friction damper according to a 16th aspect of the invention, in thefriction damper according to any one of the first to 15th aspects,further comprises at least one deformable member interposed between thesupport and the hollow cylindrical portion of the friction member.

In the invention, if the deformable member is provided as in thefriction damper according to the 16th aspect, the hollow cylindricalportion of the friction member can be uniformly brought into contactwith the rod.

The displaceable deformable member preferably has a slit and is therebyreducible in diameter as in the friction damper according to a 17thaspect, or the deformable member is formed into two-split members and isthereby reducible in diameter as in the friction damper according to an18th aspect.

As in the friction damper according to a 19th aspect of the invention,the deformable member is sufficient if it is formed of one of a rubberplate, a copper plate, and an embossed plate, which is capable ofuniformly bringing the hollow cylindrical portion of the friction memberinto contact with the rod by virtue of its deformability, particularlyin the tightening of the hollow cylindrical portion of the frictionmember against the rod by the tightening means.

As for the deformable member, a single deformable member may beinterposed between the support and the hollow cylindrical portion of thefriction member. Alternatively, however, as in the friction damperaccording to a 20th aspect of the invention, a plurality of deformablemembers may be superposed one on top of another, and may be interposedbetween the support and the hollow cylindrical portion of the frictionmember.

As in the friction damper according to a 21st aspect of the invention,the rod is preferably formed of a solid or hollow member having acylindrical surface on an outer peripheral surface thereof.

In accordance with the invention, it is possible to provide a frictiondamper which has a simple structure, is capable of reducing wear and theexfoliation of the sliding layer as practically as possible, and makesit possible to obtain stable damping characteristics over a long periodof time.

Hereafter, a more detailed description will be given of the mode forcarrying out the invention on the basis of the preferred embodimentsillustrated in the drawings. It should be noted that the invention isnot limited to these embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front cross-sectional view of a preferred embodiment of theinvention;

FIG. 2 is a cross-sectional view, taken in the direction of arrowsII-II, of the embodiment shown in FIG. 1;

FIG. 3 is an explanatory diagram of a support in accordance with theembodiment shown in FIG. 1;

FIG. 4 is a perspective view of a friction member in accordance with theembodiment shown in FIG. 1;

FIG. 5 is a partially cutaway bottom view of the embodiment shown inFIG. 1;

FIG. 6 is an explanatory diagram of the friction member in accordancewith the embodiment shown in FIG. 1;

FIG. 7 is an explanatory diagram of an example in which the embodimentshown in FIG. 1 is used in a detached house;

FIG. 8 is a load-displacement characteristic diagram in accordance withthe embodiment shown in FIG. 1;

FIG. 9 is an explanatory cross-sectional view using another example ofthe support in the embodiment shown in FIG. 1;

FIG. 10 is an explanatory cross-sectional view of the other example ofthe support shown in FIG. 9;

FIG. 11 is a cross-sectional view of another preferred embodiment of theinvention;

FIG. 12 is a perspective view of the deformable member shown in FIG. 11;

FIG. 13 is a cross-sectional view of still another preferred embodimentof the invention; and

FIG. 14 is a perspective view of the friction member and the deformablemember shown in FIG. 13.

EMBODIMENTS

In FIGS. 1 to 5, a friction damper 1 in accordance with this embodimentis comprised of a base body 2; a plurality of, or in this embodimentthree, supports 4, 5, and 6 which are respectively secured to anelongated member 35 of the base body 2, have a through hole 3, and arearranged in an axial direction X; a rod 7 which extends in such a manneras to pass through the respective through holes 3 of the supports 4, 5,and 6, and is movable in the axial direction X with respect to thesupports 4, 5, and 6; friction members 9, 10, and 11 each of which has ahollow cylindrical portion 8 interposed between each of the supports 4,5, and 6 and a cylindrical main body portion 85 of the rod 7 in acorresponding through hole 3 of the support 4, 5, or 6, the frictionsmembers 9, 10, and 11 being fixed immovably with respect to the relativemovement of the rod 7 in the axial direction X with respect to the basebody 2 and being provided with respect to the respective supports 4, 5,and 6; and tightening means 12, 13, and 14 provided for the supports 4,5, and 6 so as to tighten the respective hollow cylindrical portions 8of the friction members 9, 10, and 11 onto the main body portion 85 ofthe rod 7.

The base body 2 includes a rectangular tubular body 21 extending in theaxial direction X; one cover 25 secured to an inner surface of one endportion 22 of the tubular body 21 by means of screws 23 and having athrough hole 24 through which the main body portion 85 of the rod 7 ispassed through; and another cover 30 secured to an inner surface of theother end portion 26 of the tubular body 21 by means of screws 27 andhaving a U-shaped fitting 28 attached thereto by a bolt 29. The tubularbody 21 has the elongated member 35 with a U-shaped cross section, aswell as a plate member 37 attached to the cover 25 and the cover 30 atboth ends by means of screws 36 so as to close opening planes of theelongated member 35. The fitting 28 for attaching the base body 2 to oneof the pair of members which are displaced relative to each other, e.g.,a lower beam 38 of a detached house as the structure, as shown in FIG.7, has a pair of through holes 39 for the insertion of a shaft member.

The base body 2 is so arranged as to be capable of being rotatablyattached to the lower beam 38 by means of a shaft member 40 which isinserted in the through holes 39 of the fitting 28 secured to the cover30.

Since the supports 4, 5, and 6 are respectively formed in a mutuallysimilar manner, a detailed description will be given below of thesupport 4, and the supports 5 and 6 will be described, as required.

As particularly shown in FIG. 3, in addition to the through hole 3, thesupport 4 shaped substantially in the form of a rectangularparallelepiped has a slit 41 communicating with the through hole 3 sothat the diameter of the through hole 3 can be reducible. Further, thesupport 4 has an internally threaded hole 42 and a bolt insertion hole43 disposed in face-to-face relation to the internally threaded hole 42in alignment therewith. The support 4 is secured to the inner peripheralsurface of the elongated member 35 by means of screws 44.

Since the friction members 9, 10, and 11 are respectively formed in amutually similar manner, a detailed description will be given below ofthe friction member 9, and the friction members 10 and 11 will bedescribed, as required.

As particularly shown in FIG. 4, in addition to the hollow cylindricalportion, the friction member 9 has a collar 51 formed integrally withthe hollow cylindrical portion 8. The collar 51 of the friction member 9is superposed on the collar 51 of the friction member 10 having thehollow cylindrical portion 8 interposed between the support 5 and themain body portion 85 of the rod 7 in the through hole 3 of the adjacentsupport 5. The collar 51 is disposed between mutually opposing sidesurfaces 52 and 53 of the supports 4 and 5 by being clamped by the sidesurfaces 52 and 53. Thus, the friction member 9 is fixed immovably withrespect to the relative movement of the rod 7 in the axial direction Xwith respect to the base body 2 at the collar 51.

It should be noted that the friction member 11, which has the hollowcylindrical portion 8 interposed between the support 6 and the main bodyportion 85 of the rod 7 in the through hole 3 of the support 6, is fixedimmovably with respect to the relative movement of the rod 7 in theaxial direction X with respect to the base body 2 at the collar 51disposed between mutually opposing side surfaces 54 and 55 of thesupport 6 and the cover 25 adjacent to the support 6 by being clamped bythe side surfaces 54 and 55.

The friction member 9 is fabricated as follows. As shown in FIG. 6, asliding layer 63 formed of polyimide resin, tetrafluoroethylene resin,or a mixture thereof is first formed on one surface of a metal sheet(mesh-like metal sheet) formed of an expanded metal or metal wire net 62having a multiplicity of meshes 61, in such a manner as to fill themeshes 61 of the metal sheet. The metal sheet having such a slidinglayer 63 formed on one surface thereof is cut into strips. This metalsheet in the form of strip is convoluted by one turn such that thesliding layer 63 is set on the inner peripheral surface side, therebyforming a hollow cylinder having a slit formed between mutual abutmentends 64 and 65 of the metal sheet and extending from one end face to theother. Subsequently, by subjecting this hollow cylinder to pressforming, the friction member 9 is fabricated which includes the hollowcylindrical portion 8 having the expanded metal or metal wire net 62 asa mesh-like base material disposed on the radially outer peripheralsurface side and the synthetic resin-made sliding layer 63, which fillsthe meshes 61 of the expanded metal or metal wire net 62 serving as themesh-like base material, is formed on one surface of the expanded metalor metal wire net 62, and is disposed on the radially inner peripheralsurface side, as well as the collar 51 formed integrally with the hollowcylindrical portion 8.

The hollow cylindrical portion 8 of the friction member 9 thusfabricated has a slit 73 extending from one end face 71 to the other endface 72 in the axial direction X, and is hence capable of undergoing areduction in diameter. The collar 51 of the friction member 9 also has aslit 74 extending radially in such a manner as to continue from the slit73. The hollow cylindrical portion 8 is thereby made reducible indiameter.

In the friction member 9, the sliding layer 63 containing at least oneof polyimide resin and tetrafluoroethylene resin is disposed on theradially inner peripheral surface side of the hollow cylindrical portion8 so as to be brought into contact with the main body portion 85 of therod 7 slidably in its axial direction X.

Since the tightening members 12, 13, and 14 are also respectively formedin a mutually similar manner, a detailed description will be given belowof the tightening member 12, and the tightening members 13 and 14 willbe described, as required.

The tightening member 12 has a bolt 81 which is inserted into thesupport 5 through the bolt insertion hole 43 and is threadedly engagedwith the internally threaded hole 42 of the support 5, so as to becapable of reducing the width of the slit 41. The arrangement providedis such that as the state of threaded engagement with the internallythreaded hole 42 is changed by turning the bolt 81, the width of theslit 41 is reduced to reduce the diameter of the through hole 3 of thesupport 5, and the hollow cylindrical portion 8 of the friction member 9is caused to undergo a reduction in diameter through this reduction indiameter, to thereby tighten the hollow cylindrical portion 8 againstthe main body portion 85 of the rod 7.

The rod 7 has the cylindrical main body portion 85 and threaded portions86 and 87 respectively formed integrally at opposite ends, as viewed inthe axial direction X, of the main body portion 85. A detent nut 88 isthreadedly engaged with the threaded portion 86, while a U-shapedfitting 91 having through holes 90 for the insertion of a shaft memberis fixed to the threaded portion 87 by means of a nut 89 threadedlyengaged with the threaded portion 87.

The rod 7 is made capable of being rotatably attached to the other oneof the pair of members which are displaced relative to each other, e.g.,an upper beam 92 of a detached house as the structure, as shown in FIG.7, by the threaded portion 87 by means of a shaft member 93 inserted inthe through holes 90 of the fitting 91.

As shown in FIG. 7, the above-described friction damper 1 is used suchthat the base body 2 is rotatably attached to the lower beam 38extending between columns 96 by means of the fitting 28, the shaftmember 40, and an attaching plate 95, while the rod 7 is rotatablyattached to the upper beam 92 extending between the columns 96 by meansof the fitting 91, the shaft member 93, and an attaching plate 97.

When the upper beam 92 is displaced in a lateral direction H relative tothe lower beam 38 due to an earthquake, the rod 7 moves in the axialdirection X relative to the base body 2. In the relative movement of therod 7 in the axial direction X with respect to the base body 2, suchrelative movement energy, e.g., the relative displacement energy of theupper beam 92 in the lateral direction H with respect to the lower beam38, is absorbed by the friction between the hollow cylindrical portion 8of the friction member 9 and the main body portion 85 of the rod 7.Thus, the relative displacement of the upper beam 92 in the lateraldirection H with respect to the lower beam 38 is damped at an earlyperiod.

According to the friction damper 1, the base material of the frictionmember 9 is the mesh-like material comprising the expanded metal ormetal wire net 62; the sliding layer 63 of the friction member 9 isformed on one surface of the expanded metal or metal wire net 62 in sucha manner as to fill the meshes of the expanded metal or metal wire net62; and such a sliding layer 63 is disposed on the radially innerperipheral surface side of the hollow cylindrical portion 8 so as to bebrought into contact with the rod 7 slidably in its axial direction X.Therefore, it is possible to avoid wear with respect to the main bodyportion 85 of the rod 7 as practically as possible, and obtain desiredstable friction between the main body portion 85 and the hollowcylindrical portion 8. Furthermore, it is possible to avoid theexfoliation of the sliding layer 63. Hence, it is possible to obtainstable damping characteristics over a long period of time.

In addition, according to the friction damper 1, the hollow cylindricalportion 8 of the friction member 9 can be tightened onto the main bodyportion 85 of the rod 7 by the tightening means 12 by being optimallyadjusted. Therefore, by a simple operation, optimal frictionalresistance can be obtained for the upper beam 92 and the lower beam 38which undergo relative displacement in the lateral direction H.

In addition, according to the friction damper 1, the displacement energyis adapted to be absorbed by the three friction members 9, 10, and 11.Therefore, as a result of the fact that the respective loads of thefriction members 9, 10, and 11 can be reduced, it is possible to obtainstable damping characteristics over a long period of time.

Furthermore, according to the friction damper 1, the respective frictionmembers 9, 10, and 11 are fixed immovably with respect to the relativemovement of the rod 7 in the axial direction X with respect to the basebody 2 by being clamped by the supports 4 and 5 adjoining at the collars51 and by the support 6 and the cover 25. Therefore, the respectivefriction members 9, 10, and 11 can be firmly fixed, so that it ispossible to eliminate the drawback that the friction members 9, 10, and11 are offset from the supports 4, 5, and 6.

The friction damper 1, in which the diameter of the main body portion 85of the rod 7 was 12 mm and the frictional force of the sliding layer 63of each of the friction members 9, 10, and 11 was 200 N, was fabricated.In such a friction damper 1, the rod 7 was subjected to relativedisplacement of about ±30 mm in the axial direction X with respect tothe base body 2 at 0.05 Hz, which was repeated three times, to measurethe load-displacement characteristic. The result is shown in FIG. 8.

It should be noted that although the aforementioned support 4 isintegrally formed by being provided with the through hole 3 and the slit41, as shown in FIGS. 9 and 10, the support 4 may alternatively beformed by two-split members 103 and 104 respectively having semicircularholes 101 and 102 for forming the through hole 3, thereby rendering thethrough hole 3 reducible in diameter by the two-split members 103 and104. In the support 4 formed by the two-split members 103 and 104 shownin FIGS. 9 and 10, one split member 103 is secured to the elongatedmember 35 of the base body 2 by a screw 105, while the other splitmember 104 is disposed movably in the tubular body 21 such that thesemicircular hole 102 opposes the semicircular hole 101. The tighteningmeans 12 for such a support 4 has two bolts 81 which are inserted in thesplit member 104 of the support 4 through the two bolt insertion holes43 in the split member 104, and are respectively threadedly engaged withthe two internally threaded holes 42 in the split member 103 of thesupport 4 so as to be able to reduce the width of a gap 106 between thetwo split members 103 and 104.

The friction damper 1 having the support 4 shown in FIGS. 9 and 10 isalso capable of exhibiting advantages similar to those described above.

With the above-described friction damper 1, although the hollowcylindrical portion 8 is tightened against the main body portion 85 ofthe rod 7 by causing the support 4 to come into direct contact with thehollow cylindrical portion 8 of the friction member 9, an arrangementmay alternatively be provided such that, as shown in FIGS. 11 and 12, ahollow cylindrical deformable member 112, which has a slit 111 to bereducible in diameter and is formed of a rubber plate, a copper plate,or an embossed plate, is interposed between the two-split members 103and 104 of the support 4 and the hollow cylindrical portion 8 of thefriction member 9, and the tightening of the hollow cylindrical portion8 against the main body portion 85 by the tightening means 12 by meansof the support 4 is further effected by means of the deformable member112. As the deformable member 112, which is formed of a rubber plate, acopper plate, or an embossed plate and elastically permits a slightdeformation in the radial direction, specifically a slight change in thethickness in the radial direction, is interposed between the support 4and the hollow cylindrical portion 8 of the friction member 9, it ispossible to cope with a creep deformation of the friction member 9 andthe like through the elastic deformation of the deformable member 112.As a result, the hollow cylindrical portion 8 can be uniformly pressedand abutted against the main body portion 85, thereby making it possibleto obtain appropriate frictional resistance as a whole.

In the embodiment shown in FIGS. 11 and 12, although a single deformablemember 112 is interposed between the support 4 and the hollowcylindrical portion 8, a plurality of deformable members 112 may besuperposed one on top of another, and the plurality of such deformablemembers 112 may be interposed between the support 4 and the hollowcylindrical portion 8.

In addition, although the above-described friction member 9 has thehollow cylindrical portion 8 and the collar 51, is reducible in diameterby means of the slit 73, and is integrally formed, the friction member 9may alternatively be formed as follows. Namely, as shown in FIGS. 13 and14, the friction member 9 may be formed by being provided with a splitmember 123 consisting of a hollow semicylindrical portion 121 and a halfcollar 122 formed integrally with the hollow semicylindrical portion 121as well as a split member 133 consisting of a hollow semicylindricalportion 131 and a half collar 132 formed integrally with the hollowsemicylindrical portion 131. The hollow cylindrical portion 8 formed bythe hollow semicylindrical portion 121 and the hollow semicylindricalportion 131 may be formed into such two-split members 123 and 133, so asto be made reducible in diameter.

As shown in FIGS. 13 and 14, the deformable member 112 may also beformed by two-split members 141 and 142 so as to be reducible indiameter by means of the two-split members 141 and 142. The split member141 is interposed between the split member 103 and the hollowsemicylindrical portion 121, while the split member 142 is interposedbetween the split member 104 and the hollow semicylindrical portion 131.

In addition, as shown in FIGS. 2 and 9, among others, the main bodyportion 85 of the rod 7 may be formed of a solid member having acylindrical surface on its outer peripheral surface. Alternatively,however, the main body portion 85 of the rod 7 may be formed of a hollowmember, i.e., a tubular member, as shown in FIG. 13.

The invention claimed is:
 1. A friction damper comprising: a base bodyadapted to be capable of being attached to one of a pair of first andsecond members which are displaced relative to each other; first andsecond supports each secured to said base body and having an innercircular surface defining a circular through hole, said first supporthaving only one slit communicating with the circular through hole ofsaid first support so as to be reducible in diameter of the circularthrough hole of said first support, said first and second supports beingmutually adjacent in an axial direction; a cylindrical rod which extendsthrough the circular through hole of said first and second supports, hasan outer circular surface, is movable in the axial direction withrespect to said first and second supports, and is adapted to be capableof being attached to another one of the pair of first and secondmembers; a friction member which has a hollow cylindrical portioninterposed between the inner circular surface of said first support andthe outer circular surface of said rod in the circular through hole ofsaid first support, and only one collar united with said hollowcylindrical portion and is fixed immovably with respect to the relativemovement of the rod in the axial direction with respect to said basebody, said hollow cylindrical portion which has a radially outerperipheral circular surface, a radially inner peripheral circularsurface, and a slit extending from one end face to another end facethereof in the axial direction so as to be reducible in diameter of theradially inner peripheral circular surface, having a mesh base materialdisposed on a radially outer peripheral circular surface side thereofand a synthetic resin-made sliding layer filling meshes of said basematerial and formed on one surface of said base material, said slidinglayer being disposed on a radially inner peripheral circular surfaceside of said hollow cylindrical portion so as to be brought into contactwith said rod slidably in the axial direction; a tightening member totighten said hollow cylindrical portion of said friction member againstsaid rod to reduce the diameter of the radially inner peripheralcircular surface of said hollow cylindrical portion of said frictionmember through the reduction in diameter of the circular through hole ofsaid first support; and at least first deformable member interposedbetween said inner circular surface of said first support and theradially outer peripheral circular surface of said hollow cylindricalportion of said friction member to uniformly bring the hollowcylindrical portion of the friction member into contact with the rod byvirtue of its deformability in the tightening of the hollow cylindricalportion of the friction member against the rod by the tightening member,said deformable member which is formed separately from said frictionmember, having a slit so as to be reducible in diameter of saiddeformable member, said first and second supports between which saidcollar is disposed, clamping said collar so as to fix said frictionmember immovably with respect to relative movement of said rod in theaxial direction with respect to said base body, said tightening memberhaving a bolt threadedly engaged with said first support to reduce thewidth of the slit of said first support, and to thereby reduce the widthof the slits of the friction member and the deformable member.
 2. Thefriction damper according to claim 1, wherein said base materialcomprises one of an expanded metal and a metal wire net.
 3. The frictiondamper according to claim 1, wherein said sliding layer containspolyimide resin.
 4. The friction damper according to claim 1, whereinsaid sliding layer contains tetrafluoroethylene resin.
 5. The frictiondamper according to claim 1, wherein said base body includes a tubularbody; one cover secured to one end portion of said tubular body andhaving a circular through hole through which said rod is passed; andanother cover secured to another end portion of said tubular body andhaving a fitting attached thereto for being attached to the one of thepair of first and second members, said first and second supports beingsecured to an inner peripheral surface of said tubular body.
 6. Afriction damper comprising: a base body adapted to be capable of beingattached to one of a pair of first and second members which aredisplaced relative to each other; first and second supports each securedto said base body and having a through hole, said first support havingonly one slit communicating with said through hole of said first supportso that the diameter of said through hole of said first support can bereducible, said first and second supports being mutually adjacent in anaxial direction; a rod which extends through the through holes of saidfirst and second supports, is movable in an axial direction with respectto said first and second supports, and is adapted to be capable of beingattached to another one of the pair of first and second members; and afriction member which has a hollow cylindrical portion interposedbetween said first support and said rod in the through hole of saidfirst support, and only one collar united with the hollow cylindricalportion, said first and second supports between which said collar isdisposed, clamping said collar so as to fix said friction memberimmovably with respect to relative movement of said rod in the axialdirection with respect to said base body, said hollow cylindricalportion of said friction member having a mesh base material disposed ona radially outer peripheral surface side thereof and a syntheticresin-made sliding layer filling meshes of said base material and formedon one surface of said base material, and said sliding layer beingdisposed on radially inner peripheral surface side of said hollowcylindrical portion so as to be brought into contact with said rodslidably in the axial direction.